LEDs are widely used in various applications including, but not limited to, area lighting, indoor lighting, and backlighting. LEDs are more efficient at generating visible light than many traditional light sources. However, the implementation of LEDs for many traditional light source applications has been hindered by the amount of heat build-up occurring within the electronic circuits of the LEDs. Heat build-up reduces the LEDs light output, shortens the LEDs lifespan and can eventually cause LEDs to fail.
Heat sinks are being used with LEDs and provide a pathway for absorbing the heat generated from the LEDs and for dissipating the heat directly or radiantly to the surrounding environment. Exemplary methods for manufacturing heat sinks include the casting process and the extrusion process. The casting process involves a series of steps including building a mold with specific dimensions and allowances, melting a base metal and adding a degasser component, machining the heat sink to obtain the proper dimensions, and polishing to provide a finish to the surface. The extrusion process, however, involves pushing or drawing a material through a die of the desired cross-section. Exemplary materials that can be extruded include, but are not limited to, metals, such as aluminum, copper, lead, tin, magnesium, zinc, steel, and titanium, polymers, and ceramics.
The extrusion process provides several benefits over other manufacturing processes. The extrusion process is capable of creating very complex cross-sections. The extrusion process also is able to work materials that are brittle because the material only encounters compressive and shear stresses. The process further forms finished parts having an excellent surface finish. The extrusion process also is more cost effective than other manufacturing processes.
One limitation when using an extrusion process to form a heat sink is that hollows cannot be formed without machining the heat sink to produce the hollow once the material has been extruded. A hollow is an area in the interior of the extruded product that is devoid of material but otherwise surrounded by the extruded material. Thus, an extra more costly step is involved to form the hollow within the extruded material or the hollow can be formed using the more costly casting process.
In view of the foregoing, there is a need in the art for providing a modular heat sink. There is a further need in the art for providing a modularly extruded heat sink that can be interconnected to form a shape that cannot be formed by directly from the extrusion process. Furthermore, there is a need for providing a method to form heat sink shapes having a hollow during the extrusion process.